Retro system enthusiasts have resolved the licensing issue regarding the original source codes of the CP/M operating system, which dominated computers with eight-bit processors i8080 and Z80 in the 1970s. In 2001, the CP/M code was handed over to the community cpm.z80.de by Lineo Inc, which acquired the intellectual property of Digital Research, the company that developed CP/M. The license for the transferred code allowed for use, distribution, and modification, with the note that this right is granted to the community, developers, and maintainers from the cpm.z80.de website.
Due to this note, developers of CP/M related projects, such as the CP/Mish distribution, refrained from using the original CP/M code for fear of violating the license. One of the enthusiasts interested in the CP/M code wrote to Bryan Sparks, the president of Lineo Inc and DRDOS Inc, asking for clarification on the mention of a specific site in the license.
Bryan clarified that he did not originally intend to transfer the code to just one website, and the addition only referenced a specific private case. He also provided an official clarification on behalf of the company that holds the intellectual property for CP/M, stating that the conditions defined in the license apply to all interested parties. Thus, the text of the license became essentially equivalent to an open MIT license. The source codes of CP/M are written in PL/M and assembly language. An emulator that runs in a web browser is available for familiarization with the system.
Source: opennet.ru
